Dust-tight watch crown



Feb. 21, 1950 FEURER 2,497,935

DUST-TIGHT WATCH CROWN Filed July 11, 1947 BY l m,

Patented Feb. 21, 1950 DUST-TIGHT WATCH CROWN Robert Feurer, Jackson Heights, N. Y., assignor to vFeurer Bros'., Inc., New York, N. 1C, a corporation of New York Application July 11,

" 1 Claim.

The invention disclosed in this patent application relates to watch crowns and the main object of the invention is to provide a simple, practical and thoroughly reliable dust-tight connection between the crown and the case of a :watch.

. Particular objects of the invention are to provide such structure in a form which will adapt itself to various angles and degrees of eccentricity between the watch stem and case to maintain a periectseal and proper operating relations under all such circumstances.

Special objects of the invention are to accomplish all the foregoing in a simple, inexpensive construction, compact and small, so as to be accommodated within small ornamental crowns.

Other special objects are to accommodate the sealing means all within the body of the crown and to confine such means to the crown when the latter is removed from the winding and setting stem.

Further objects of the invention are to reduce the number of essential parts and to accomplish this by combining a portion of the sealing functions with the spring for maintaining the seal in the self-adjusting, closed relation.

Other desirable objects and the novel features through which the purposes of the invention are attained are set forth or will appear in the course of the following specification.

The drawing accompanying and forming part of the specification illustrates certain present practical embodiments of the invention. Structure, however, may be modified and changed as regards the immediate illustration, all within the true intent and broad scope of the invention as hereinafter defined and claimed.

Figure 1 in the drawing is a broken cross sectional view illustrating one form of the new selfadjusting and self-sealing watch crowns as applied to a watch stem and cooperating with a watch case;

Fig. 2 is a similar View of another form of the invention;

Fig. 3 is a broken sectional detail of a modification.

As appears in the several views, the watch crown 5 of the present invention is made with a relatively deep annular cut 6 to contain the sealing means, and with a central tubular projection 1 internally screw threaded to be removably engaged with the correspondingly screw threaded winding and setting stem 8.

The wall 9 of the watch case is made with an opening considerably larger than the stem and 1947, Serial No. 760,387

this opening is beveled as represented at 10, to forma seat for a correspondingly beveled or tapered sealing washer H loosely surrounding the tubular stem 7 and loosely received in the annular chamber 5 in the'crown. This looseness is such as to permit the sealing washer to adjust itself to various degrees of eccentricity and relative angularity between the case and stem, so that the washer may adjust itself to a proper sealing fit in the watch case opening l0, despite any ofi-center position of the stem or out of true angularity between stem and case.

A definite seal is provided between the crown and the back of the beveled washer and this seal is, in effect, the spring for maintaining the washer in its self-adjusted sealing engagement with the case.

In Fig. 1 the combination sealing spring consists of four dished or conical spring washers l2, I3, I 4, l 5, arranged in pairs and with a fiat spring washer l6 between such pairs.

The spring washers of each pair are arranged back to back with their inner edges in contact and their outer edges engaged, respectively, with the back wall I! of the annular cavity in the crown and with the outer edge portion of the intermediate flat washer 16.

The individual spring washers I4, l5, of the inner pair are similarly disposed back-to-back with their inner edges in contact and their outer edges engaged with the intermediate flat washer l6 and with the fiat back face l8 of the beveled sealing washer or sleeve II.

All the sealing and spring forming washers I2, I3, l4, I5 and Hi, are shown as loosely disposed within the annular cavity 5 and about the central screw stud I so as to be free for any required self-adjusting side motion in respect to both the body of the crown and the central tubular screw stud.

The sealing and spring forming washers may be made of beryllium copper alloy and the parts are so proportioned that they Will be placed under tension as the beveled sealing sleeve or ring l meets the case and the crown is screwed fully in place on the same. This tension is preferably such as to maintain an effective seal from the back of the crown to the case during both setting and winding positions of the crown.

To maintain the parts in the assembled relation when the crown is removed from the stem, the inner end of the screw stud 1 may be flanged as indicated at l 9 to act as a retainer engageable by the inner end of the sealing member H. It is contemplated, however, that the retainer flange instead of being formed on the end of the screw stud, may be formed on the crown about the outer edge of the annular cavity 6, in position to be engaged by the outer periphery of the sealing member.

Fig. 2 illustrates an embodiment of the invention wherein the spring and outer sealing member are all in one instead of in several pieces.

This spring sealing member is shown as a flexible, elastic, rolled metal bellows 20 loose in the crown cavity and about the screw stud and having more or less fiat flanges 2|, 22, at its outer and inner ends in laterally Jslidable sealing engagement with the back wall If! of the crown and the back face l8 of the beveled inner case engaging sealing member II.

This construction also allows for all self-adjusting movements required to maintain fully sealed relations between the'crown and the case.

Both constructions are relatively simple, the parts are few and can be readily assembled, the cost of such constructions'is reasonable and a fully dust-tight relation between crown and case is maintained at all times regardless of imperfections as to alignment and angularity, variations in the size, etc.

Fig. 3 shows how the sealing washer may be retained in the crown by a flange 23 turned inward at the outer periphery of the annular cavity in position to be engaged by a narrow flange 24 on the rim of the sealing washer.

What is claimed is: A dust-tight watch crown for a watch case having a. beveled seat about the stem and comprising a crown body having a deep annular cavity about a central internally screw threaded stud for engagement on the stem, a sealing washer loose in the annular cavity and loose about the tubular stud and having a beveled inner face for sealing engagement with the beveled seat in the case and an expansion spring in the annular cavity back of said sealing washer and extending continuously as a flexible spring sealing wall from the back of the cavity to the back of said sealing washer, said seal forming spring being composed of dished spring washers in back-to- :back relation in pairs and with the pairs separated by a substantially flat washer.

ROBERT FEURER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,910,078 Wilsdorf May 23, 1933 2,208,419 Greenberg l July 16, 1940 2,237,860 Bolle Apr. 8, 1941 FOREIGN PATENTS Number Country Date 204,001 Switzerland July 1, 1939 368,866 Great Britain Mar. 17, 1932 

